To provide dedicated access to footprinting technology, beamline X9A at the National Synchrotron Light Source has been constructed along with a dedicated stopped flow instrument to allow footprinting studies for our expanded group of investigators. The beamline accepts up to 5 milliradians of white beam, with a flux density of 109 photons/s/mm2/0.07% bandwidth over an effective energy range of 3-30 keV. The completion of the beamline has enhanced the productivity of this core project, accelerating both the core and collaborative research programs tremendously. Our Resource is the world leader in this technology and the availability of a dedicated beamline will continue our leadership in this area. We are now routinely conducting Hfootprinting studies on 10 - 20 msec and longer timescales with our Hstopped flow device. Major advances in understanding RNA folding have Hbeen accomplished and studies of protein-DNA complex formation have Hbeen initiated.